Well 650 watt power supplies is more than enough with ample headroom for future upgrades.
The 3570k consumes around 75 watts (probably less than that)\
GTX 670 uses around 170 watts
Those two major power drawing components don't add up to be very much.
However no harm done getting a bigger power supply but truth is you will be wasting more money on it when you wont use it. Generally the trend with most video cards is they get more efficient with each new series.